Abstract

We develop a model for the excitation of erbium ions in erbium-doped siliconnanocrystals via coupling from confined excitons generated within the siliconnanoclusters. The model provides a phenomenological picture of the exchange mechanism and allows us to evaluate an effective absorption cross section for erbium of up to four orders of magnitude higher than in stoichiometric silica. We address the origin of the 1.6 eV emission band associated with the siliconnanoclusters and determine absorption cross sections and excitonic lifetimes for nanoclusters in silica which are of the order of and 20–100 μs, respectively.